


The Babysitter

by VicesVsVirtues



Category: Shadowhunters (TV), The Mortal Instruments Series - Cassandra Clare
Genre: Babysitting, Christmas Party, F/M, Shadowhunters - Freeform, Short Story, the mortal instruments - Freeform
Language: English
Status: Completed
Published: 2017-11-23
Updated: 2017-11-30
Packaged: 2019-02-05 22:29:46
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 7
Words: 4,156
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12803760
Author URL: https://archiveofourown.org/users/VicesVsVirtues/pseuds/VicesVsVirtues
Summary: Jace is left, literally, holding the baby. At a Christmas party no less.Or the one where: When Magnus and Alec get called out by one of Magnus’ clients, Jace suddenly becomes a reluctant babysitter at The Institute’s Christmas party.Written for a Christmas Fic Exchange***takes place AFTER the main books and Shadowhunter Academy, so there will be apoilers*****Crossposted to Wattpad**Updating daily





	1. Chapter 1

**Author's Note:**

  * For [HeadGirl91](https://archiveofourown.org/users/HeadGirl91/gifts).



> Thank you to RavenclawPixieRose for organising the exchange. It's been fun

Christmas Fic Exchange:

 **Written for** : HeadGirl91

 **Written by** : ViceVsVirtues

 **Fandom** : TMI

 **Pairing** : Clace

 **Prompt used** : Accidental baby acquisition

 **Summary** : When Magnus and Alec get called out by one of Magnus’ clients, Jace suddenly becomes a reluctant babysitter at The Institute’s Christmas party.

****

**_The Babysitter:  
Chapter One:_ **

****

“I hate wearing suits.” Jace muttered to himself as he fussed with the bowtie he had been instructed to wear. “What’s wrong with my regular clothes?”

This question was directed at Alec who was hovering in the doorway to his room with a smile on his face.

“Because this is a party, and it is essential for people to dress up at parties.”

“Magnus is rubbing off on you… and not in a good way.” Jace grumbled, making Alec laugh out loud. “Anyway, where is _the High Warlock of Brooklyn?_ This party was his idea after all.”

Alec walked into the room and pushed Jace’s hands to one side, taking over tying the tie. His own suit and tie were, naturally, perfect. They also had a hint of sparkle, indicating Magnus’ influence.

“He’s getting ready at the loft with Max. He’ll be here shortly.” With a flourish that was very un-Alec, the tie was finished with. “There, you look perfect.”

“This party better be worth it.” Running a finger under his collar, Jace grunted to show his lack of comfort. Without saying anything else, he walked over to the dresser by the window and picked up a seraph dagger and slid it into his left boot.

“Why are you adding that to your outfit? Who do you think would attack a Christmas Party?”

“Alec, we’re Shadowhunters. We have to be ready for every eventuality, you know that.”

“Sure… I have to go. Magnus and Max will be here soon, and I need to make sure everything’s ready.” Alec walked out of the room before Jace could even manage to respond. Chuckling to himself, he grabbed his phone and fired off a text to Clary.

_Please tell me you’re here. I’m already over this whole thing._

After waiting a whole five minutes, with no reply, Jace shoved his phone in his pocket. Giving himself one final look over in the mirror, he took a deep breath and left the room.


	2. Chapter Two

**_Chapter Two:_ **

****

Jace almost didn’t recognise the Institute when he exited the elevator into the lobby. Magnus had clearly wielded his magic with a flourish to make the ballroom that Jace had forgotten even existed look like a winter wonderland. He’d always loved winter in New York, but the effect Magnus had had on the building was immense.

Walking over to the table at the back of the room that was laden down with food, Jace grabbed a glass and poured himself some of the bright red punch. Looking round, he watched the other Shadowhunters milling around, seemingly just as uncomfortable in their clothes as Jace.

There was no sign of any of the Lightwoods, Simon, or Clary which annoyed him. He was ready, well in time for the start of the party, and there was no one to entertain him or to complement him on his appearance. If he was going to have to go all out, he at least wanted someone to actually notice the effort he’d made.

His phone bleeped from his pocket, indicating Clary had finally replied to his text.

_On our way x._

A grin spread across Jace’s face at the thought of seeing Clary. Ever since Simon had graduated from the Shadowhunter Academy and become Clary’s parabatai, she’d been busy helping him adjust to his new life within the shadow world.

Secretly, Jace was proud of Simon. Not many people would have been able to cope with all the crap that had been flung at him over the past few years. Becoming a vampire, being given the mark of Cain, being restored to human and losing his memories thanks to a trip to Edom; followed by two gruelling years at the academy. Each thing on their own wasn’t easy to deal with, but add them all together and it was any wonder that Simon was even able to walk and talk at the same time. Not that Jace would say that to his face. He’d never even admitted it to Clary.

However, Lewis─ Lovelace now, had dealt with it the only way he knew how to. By being his usual nerdy and annoying self. When Jace had gone to visit under the guise of being an instructor for a couple of days, Simon had looked awful, but he was coping with the support of his academy friends. Some of whom hadn’t made it as far as him.

“Jace, you look wonderful.” Maryse’s voice rang out across the almost empty room and jolted him out of his thoughts. She rushed towards him and with a wide smile, Jace hurried to meet her, their arms wrapping around one another fondly.

“So do you.” Jace held the woman he considered his mother at arm’s length, admiring her. Ever since she and Robert had separated, she had softened somewhat, yet still managed to exude an inner strength her family were proud of.

“Are Alec and Magnus here yet?” What she was really asking was if Max was here at the institute yet. She still hadn’t fully come to terms with Alec’s relationship with Magnus, but since they’d adopted the abandoned warlock baby that Simon had found during his time at the academy, she had become a little more accepting. Both she and Robert doted on their grandson, named in honour of their slain youngest child.

“Alec’s here, but Magnus and Max will be soon.” His words widened the smile on her face.

“Please excuse me while I go and find Alec.” She began to walk away, but quickly turned back to him. “If you see Isabelle, please let her know where I am.” Jace nodded his agreement.

He wasn’t left standing alone for too long. As more and more guests arrived, more than a few of them approached him to make small talk. He even knew the names of a lot of them, but some simply wanted to be seen speaking with the ‘famous Jace Herondale’, even if just for a minute or so.

After dealing with ass-licking sycophants for over twenty minutes, Jace saw his chance to escape in the form of his favourite petite red-head. Excusing himself from a conversation he had no recollection of, he made his way across the room, which was now filling up, to slide his arms around her waist from behind and placed a kiss on the back of her neck.

“You scared me.” She squeaked, slapping him on his arm. Within seconds, she recovered and flung her arms around his neck and was kissing him. A proper greeting as far as Jace was concerned.

“Nice to see you too.” Jace laughed when he and Clary parted. He couldn’t stop himself looking over her petite frame, clad in a short, black, leather dress. “ _Very_ nice.”

“Stop that Jace; we’re in public.” Clary admonished him with a small laugh.

“Never stopped either of you before.” Simon noted dryly, as he looked around the room.

“Flying solo again there Lovelace?” Jace remarked as he stroked Clary’s waist as she leaned in against him. Simon’s slight flinch at the use of his new Shadowhunter name didn’t go unmissed, but nothing was said.

“Whatever, Herondale.” Without saying anything else, Simon left the two of them alone as he walked across the room to get himself a drink.

“He’s been dying all day to see Izzy.” Clary explained by way of an apology, not telling Jace anything he didn’t know. Once more, he pulled her into his arms and kissed her deeply, Simon quickly forgotten by both of them.


	3. Chapter Three

**_Chapter Three:_ **

****

After being dragged around the room for an hour by Clary, Jace was ready to leave. He hadn’t seen Alec since before the party had started and was starting to get pissed at the fact. If he had to be in the room with all these people, why wasn’t Alec suffering with him?

As if Jace’s internal grumblings had summoned him, Alec entered the room hand-in-hand with Magnus, who had Max in his arms. Everyone in the room turned to watch their entrance, smiles on all their faces.

“So sorry we’re late. The Little Blueberry here had a wardrobe malfunction.” Magnus’ voice rang out across the entire room causing a few outbursts of laughter. By the time the trio had reached the centre of the room where Maryse and Robert were waiting for them, the other guests had returned to their own conversations.

Jace and Clary wandered over to join their friends. From what Jace could gather, the ‘malfunction’ Max had suffered was actually a case of projectile vomiting after his food. Wrinkling his nose, he made sure to not stand too close to the young child as they all stood around, catching up.

“About time you came back.” He muttered to Alec once Max had been spirited away by his doting grandparents and the younger generation of shadowhunters, and Magnus, were left alone in a small cluster in the centre of the room.

“Yeah, well. Max needed to be ‘suitably attired’.” Jace knew Alec was quoting Magnus.

“I’m sure there was more to it than that.” Jace’s teasing brought a blush to Alec’s cheek. He’d only been joking, but it was obvious that his parabatai and his boyfriend indulged in some ‘daddy and daddy’ time. With a grin, he locked eyes with Alec, saying nothing. Naturally, the blush deepened making Clary slap Jace’s arm.

“Don’t tease.” She admonished, earning a soft smile of thanks from Alec who quickly left the two of them to go and speak to Izzy who had just arrived.

“Why did you ruin my fun?” Jace pouted as he looked down at the tiny love of his life.

“Because you were being mean to Alec.”

“But it’s just too easy.”

Clary rolled her eyes and went to join Simon, Izzy, and Alec who were talking about the big Christmas dinner that was planned for three days time right here at the institute.

“Oh, Clary. Your mom and Luke are still coming, aren’t they?”

Luke and Jocelyn were in Idris visiting some friends, which prevented them from attending Magnus’ grand party.

“Yes. They get back from Alicante tomorrow, giving them plenty of time.”

“Hey, Iz. Who’s er… cooking the food?” Jace had joined them, snaking his arm back around Clary’s waist.

“Don’t worry, it’s not me. Mom’s hired caterers. She wanted to make it special. I told her I could have managed, but she insisted.”

The group surrounding the beautiful shadowhunter managed to hide their relief at her words.

“I’m sure it would have been wonderful regardless of who cooked.” Simon, ever diplomatic, made sure Isabelle remained smiling.

Before anyone else could say anything else, and possibly incur Isabelle’s wrath about her cooking, the lights in the room dimmed and the DJ turned the music up. The party had started.


	4. Chapter Four

**_Chapter Four:_ **

****

The party had been in full flow for just over two hours. Jace, Alec, Magnus, and Max sat in a corner of the huge room, eating and drinking whilst making small talk about nothing and everything.

Magnus was regaling them with a tale about he and another warlock, Ragnor Fell, from their time in Peru when he was interrupted by his phone ringing from his pocket. With a frown, he looked at the name flashing on the display, his cat’s eyes widening slightly at what he saw.

“Excuse me. I need to take this.” He stood and walked away as he answered the call. Alec watched after him, a look of confusion on his own face. A few minutes later when Magnus hadn’t returned, Alec handed Max to Jace, and wandered off to find the warlock, to see what was happening.

“Wait… Alec. Come back.” Jace held the young child at arm’s length not knowing what to do with him. He hadn’t been around children since… Max Lightwood.

“Jace. I’m sorry to do this, but Magnus and I need to leave. Can you watch Max for us?” Alec sounded out of breath. “A regular client is having some… problems. We have to go, but we should be back before the end of the party.”

“Wait, Alec, no. Why can’t Maryse or Robert watch him?” he indicated the grinning toddler in his hands.

“They’ve been called away for a conference in the office with the Consul. They’ll probably be back before Magnus and I are. Isabelle’s disappeared off with Simon, so I’m sorry. You’ll have to watch him. Just play with him and talk to him. He’ll love you.”

“Well, that’s natural, but Alec. Please don’t leave me in charge of a child too young to wipe his own ass.”

Alec just laughed rather than reply, and then walked off.

“Crap.” Jace muttered to the small blue child who was now dribbling onto his pants.

:: ::

For almost an hour and a half, Jace sat in the corner of the room with Max, not having a damn clue as to what he was doing. By the time Clary and Simon returned to him, his pants were covered in drool and a sticky substance he couldn’t identify.

“Why have you been left alone with Max?” Clary asked as she looked around for Magnus and Alec.

“They got called away to deal with one of Magnus’ clients, while Maryse and Robert are on a call with the consul. I have no idea where Isabelle is.” Jace looked at Simon, in the hopes the former vampire could magic up his girlfriend to rescue Jace from babysitting duty.

“She left a few minutes ago, said she’d be back soon.” Simon didn’t look happy about the fact, but no one stopped Isabelle Lightwood doing anything she wanted. Why she would leave during the middle of a party was beyond Jace, but there was nothing he could do about it.

Clary was trying not to laugh at the situation Jace had found himself in. He glared up at her just as Max decided to start jumping up and down. Within seconds, the jumping stopped as Max suddenly vomited all over Jace’s shoes.

“By the angel! I swear, I’m going to kill Magnus and Alec when they get back.”

He grabbed the bag Alec had left by his chair, and gingerly picked Max up and stalked in the direction of his old bedroom. He could hear Clary and Simon’s laughter following him out.

“They could have offered to help me.” He grumbled as Max squealed and giggled in his ear. They got into the elevator and slowly ascended upstairs.


	5. Chapter 5

**_Chapter Five:_ **

****

Jace realised as soon as he sat Max on his bed that he had a problem. Although most of Max’s vomit had gone over Jace’s shoes that he had kicked off the moment he walked into his room, but a lot of it had gone over Max. There was no way Jace could take him back to the party covered in sick.

“Looks like you’re going to need a bath little dude.”

Max looked up at the blonde shadowhunter and grinned, a slither of fresh vomit dribbling out of the corner of his mouth. It made Jace’s stomach turn, but he knew he had to do something.

It was at that exact moment that he realised that he had _no idea_ what he was doing. Sure, he could kill demons, he could walk through hell, and he could protect the ones he loved from any threat imaginable, but clean and change a young child… that was well beyond his skill set.

“Crap. Now what do I do?”

He pulled his phone out of his pocket and dialled Alec’s number, but the call was directed straight to voicemail. Of course it did. Jace considered calling Clary up to help him, but remembering how she and Simon had laughed at him, he didn’t feel like repeating that moment.

“Looks like it’s just you and me kid.”

Max merely looked up at him, still grinning and vomited all over himself and Jace’s bed.

“Really?” Jace groaned as Max clambered to his feet and began to jump up and down on the bed, giggling loudly. “Max, stop that.”

Naturally, his words had no effect on the small, blue boy. Eventually, Jace took hold of him under the arms and carried him into the bathroom. He stood Max in the middle of the small room and began to draw a warm bath. Once the water was deep enough, he turned back to Max and assessed the situation.

Slowly, and with care, he began to remove the mini tuxedo that Magnus and Alec had dressed Max in, muttering obscenities about his friends under his breath. After almost ten minutes, he had managed to undress the child down to a diaper that looked like it was dangerously close to overflowing.

“Wonderful.”

Gingerly, Jace coaxed Max into lying on a warm towel so he could remove the diaper. Thankfully, it wasn’t full of the ‘smelly stuff’ as he referred to it as he spoke to the warlock child. Jace was also thankful that Alec and Magnus had clearly taught their son not to wriggle around too much. Once the diaper was disposed of, Jace picked Max up and deposited him into the tepid water.

The moment Max hit the water, he began to giggle again, accompanied by enthusiastic splashing. Within minutes, Jace’s clothes were soaking wet.


	6. Chapter Six

**_Chapter Six:_ **

 

Jace gave himself a once over in the mirror. As much as he hated dressing up, he didn’t feel right going back downstairs in jeans and t-shirt, but after Max throwing up all over him, he had no choice. Max was no longer dressed in his mini tuxedo─ complete with bedazzled blazer, and now wore a similar outfit to the blond shadowhunter. The main difference was that Jace was dressed all in black while Max wore a red tee and bright blue jeans.

They entered the party which was still in full swing and made their way over to the food that was spread across three large tables. Max wriggled in Jace’s arms to try and grab hold of some candy, but Jace gripped him tightly.

“After what I’ve been through to get you cleaned up, there is no way on Earth I am going to let you have candy. How about a nice, healthy carrot stick?” Jace tried to hand Max a piece of vegetable, causing the child to suddenly start screaming. Those close to him turned to stare at the two of them, accusatory looks on their faces.

“What?” Jace snapped at them, turning back to the tables of food laid out before them. Max, once more, made a grab for some candy, but was pulled away before he could make contact. As a compromise, Jace place a sandwich, a couple of carrot sticks, and some potato chips on a small plate for Max and made his way back to the corner he had left Clary and Simon.

“You’re back, finally.” Clary smiled widely at him, taking in the change of clothes both of them had undergone. “You were quite a long time.”

He could hear the laughter in her voice, and was determined not to react, but it was hard. Saying nothing, he grit his teeth and sat down, Max on the chair next to him and placed the plate of food in front of him.

Eventually, Max began eating, and not just the chips as Jace had suspected. It seemed that the little blue boy had calmed down enough to realise he liked carrot and even sandwiches. Sighing, Jace grabbed hold of his abandoned soda that was now warm and flat, and drank the whole glass in one large gulp.

“You were upstairs for over an hour. How hard is it to change a kid’s clothes?” Simon asked, not noticing the flash of fury in Jace’s eyes.

“Well, next time Magnus and Alec need a babysitter, you can have the honours and find out for yourself. Now, please keep an eye on the little guy while I dance with Clary.”

Without letting Simon verbalise a response, Jace stood up and whisked Clary onto the dancefloor.

:: ::

“I’m going to kill Alec and Magnus when they get back.” Jace muttered as he and Clary moved across the dancefloor.

“Why?”

“Why on Earth did he think it was a good idea to leave me with a child? I’m not a babysitter… I kill demons and protect the mundanes, not change diapers.” Of course, Clary giggled at his words. “It’s not funny Fray.”

“Oh, but it is.”

“You’re lucky I love you, otherwise I wouldn’t let you say these things.” He bent his head to capture her lips with his own. “But why me? Why not you, or Simon, or anyone else? It was very convenient that no one else was around when they left. I bet they’re not even having a client emergency, I bet they just wanted some alone time.”

He was getting into his stride, moaning and whining about being the one left ‘holding the baby’. Clary shut him up by placing a single finger against his lips.

“It shows how much they trust you. You may be Alec’s parabatai, but Magnus and Max are his family and those two mean the entire world to him. The fact he left something _so_ important to him in your care proves that you are more than friends, more than brothers in arms; you’re his family. Don’t make light of that.”

Jace stared at Clary, unsure how to respond. When he couldn’t find the words─ which was rare in itself─ he merely kissed her again.

:: ::

Jace sat next to Max, watching him play with a new outlook. Gone was the annoying burden he’d been left with, and in its place was a child he’d always considered family. Max turned to look at the blond shadowhunter, his smile wide. After a moment of locking eyes with each other, the little blue child pushed himself up to stand on his chair and make ‘grabby hands’ at Jace, and indication that he wanted to be held.

Without even thinking about it, Jace pulled Max into his arms and onto his lap. As soon as he was comfortable, Max Lightwood-Bane fell asleep in the safety of Jace’s strong arms.


	7. Chapter Seven

**Notes for the Chapter:**

> The final chapter. It's a REALLY short one 
> 
> Thank you everyone who has read/commented/given kudos. It means so much, and I hope you enjoyed this silly fic. I have to admit, I didn't love writing it, but in the few weeks since I finished and began posting, I've left it alone. I've now read through it as I've been posting, and I actually adore this short story. It's silly, funny, and fluffy. What more do you want from a Christmas story?
> 
> I honestly hope the recipient has loved it, and I want to thank Michelle for organising the exchange.

**_Chapter Seven:_ **

 

Alec and Magnus returned to the party looking a little worse for wear. Alec’s shirt was torn and Jace could have sworn that one of Magnus’ eyebrows was smoking slightly, but they looked unharmed.

“About time you two got back.” He muttered, keeping his voice so he wouldn’t wake Max up.

“Sorry… it was a bit of mess, but all is sorted now.” Magnus spoke with his usual casual air, but when he saw how peacefully his son was sleeping in Jace’s arms, his face softened. Ever since Simon had found Max as a baby in the grounds of the Shadowhunter Academy, Magnus had adored that little boy.

“How was he?” Alec asked, his voice as soft as the look of love in his eyes.

“Full of barf.”

“Oh… sorry?”

Carefully, Alec plucked Max from Jace’s arms and laid him against his shoulder.

“Believe me, sorry doesn’t begin to cut it, parabatai.”

Clary was laughing again, watching Jace. Although his voice was sharp, his golden eyes told a completely different story. He may not have spent much time with Max, but the little blueberry had wormed his way into Jace’s heart, had won him over with his being so innocent and adorable.

“I’ll make it up to you.” Alec promised, a knowing smile on his face.

“Yes, yes you will. Can I now spend the rest of the evening with my girlfriend?”

“Go on with you. Babysitting duties are over.” Magnus waved his ringed hands, effectively dismissing the couple.

Jace and Clary stood and walked away from their seats. Rather than head back onto the dancefloor, Jace led her by the hand out of the room and to the elevator.

“Where are we going?” Clary asked, a small smile on her face.

“Seeing as we’ve hardly been able to spend any time together, I thought we could have a bit of alone time.”

“Oh, really?”

Without answering, Jace pulled a sprig of mistletoe out of his pocket and held it above their heads. With a grin, Clary leaned into him, their lips meeting in a soft kiss.

:: ::

Jace managed to open his bedroom door without letting go of Clary, or breaking their kiss. When he closed the door, it took a minute for the smell to hit the pair of them.

“What on earth is that?” Clary asked, covering her mouth and her nose with her hand. Jace merely groaned as he spied the bed, still covered in vomit.

 

**_::The End::_ **

 

**Author's Note:**

> I'd love to hear your thoughts


End file.
